Pipe and nut wrench.



H. F. HOFFMAN.

PIPE AND'NUT WRENCH.

APPLIVCATION FILED NOV. 11. I916.

1 78,553. Patented Sept. 10, 1918.

A TI'ORIVEYS ml "cums Peru-us 0a.. Pnamnum. wasunvcmu. n. c.

HENRY F. HOFFMAN, OF NEW YORK, N. Y.

PIPE AND NUT WRENCIH.

Specification of Letters Patent.

Patented Sept. 10, 1918.

Application filed November 11, 1916. .Seria1No.130,787.

To all whom it may concern Be it known that I, HENRY F. HOFFMAN, a citizen of the United States, and a resident of the city of New York, Stapleton, borough of Richmond, in the county of Richmond and State of New York, have invented a new and Improved Pipe and Nut WVrenc h, of which the following is a full, clear, and exact description.

This invention relates to quick adjustment of pipe or nut wrenches of the type covered especially by Letters Patent of the United States, No. 1,070,343, issued to me on August 12, 1913, which patent fully describes the automatic action of the invention with re spect to the adjustment of the movable jaw.

Among the objects of this present improvement is to provide a new specific form of locking dog for the adjustable jaw.

Another object of the invention is to simplify the construction and increase the strength and reliability of the pivoted yoke or that portion which carries the dog.

With the foregoing and other objects in view the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which Figure 1 is a side elevation of the handle and jaw portions of the wrench with the yoke in vertical section, the wrench being shown adjusted for operation on a pipe; 3

Fig. 2 is a diagrammatic view of the yoke and dog showing. the manner of detachment of the dog from the yoke;

Fig. 3 is ahorizontal section on the line 33 of Fig. 1, but omitting the jaw portions of the wrench; I

Fig. 4 is a perspective detail view of the yoke separated from the other parts; and

Fig. 5 is a similar view of the dog detached.

Referring now more particularly to the drawings, I show a nut and pipe wrench comprising relatively stationary and movable aws 10 and 11 respectively. As in the previous patent mentioned, the stationary jaw is provided with a handle or shank 12 of any suitable construction or length, and the movable jaw is provided with a shank 13 d sposed above and approximately parallel to the shank 12. The inner end of the shank 13 is provided with a pivoted member 14 constituting a combined finger piece and lock for controlling the movements of the aw ll both longitudinally and angularly with respect to the stationary jaw, as fully set forth in my. previous patent.

The yoke shown as a whole at 15 is made preferably of a single piece of tubular material and consists of side plates 16, a top plate 17 and a connecting bar 18 at the bottom. These parts are all integrally connected, the side plates being parallel to each other as are also the top and bottom members. This yoke may be made as a drop forging, as a casting or in any other convenient manner. The space between the top and bottom plates 17 and 18 is sufficient to accommodate the shanks 12 and 13 therein and affords sufficient clearance for a limited amount of pivotal movement of the yoke around the axis of a main pivot pin 19 passing transversely through holes 20 formed in the side plates 16 and the lug or hub 21 just within the stationary head 10. The head is formed with concave shoulders 22 concentric with the axis of the pin 19, whereby the similarly formed lugs or projections 23 of the side plates are directly supported against the stationary head and whereby the main strain upon the wrench is borne by the stationary head rather than by the pin 19.

A light leaf spring 24 secured to the shank 12 acts normally upwardly against a pin 25 extending laterally through the holes 26 of the yoke between the shanks 12 and 13, thetendency of which is to cause the yoke to swing in a contra-clockwise direction around the pivot 19, as viewed in Fig. 1.

The 'dog above referred to is indicated as a whole at 27 and comprises a substantially rectangular body 28 having flat parallel sides having snugfit against the inner surfaces of the side walls 16 of the yoke. The plate 17 at the topof the yokeis preferably rounded or semi-cylindrical at its inner edge, as indicated at 17*, while the outer edge ofthe same is less rounded. In other words, the preferred form is that indicated in Fig. 2, in'which said outer edge is approximately square, but rounded on the side adjacent to the dog at 17".- The polnts 29 of the side plates 16 of the yoke project slightly beyond the outer edge of the plate 17 and curve neatly and gracefully around end30 of the d g confo ms to of the yoke and fills the space between them.

At the inner end of the body 28, the dog is provided with an outwardly projecting hook 31 which embraces or fits snugly around the semi-cylindrical edge 17. The edge 17 a constitutes a fulcrumor pivot around which the dog is adapted to be turned in assembling the plate 17, the dog may then be forced directly out from, between the side plates 16 and the same or another dog maybe put in its place by reversal of these movements.

A tail piece 321 extends inwardly from the hook 31 in a general direction parallel to the shanks of the wrench, and if desired the dog may be provided on opposite sides of the tail piece with shoulders 33 which are adapted to abut squarely against the inclined edges 16. of the side plates in normal condi tion'of the wrench. The dog is provided with a series of teeth 34 which cooperate directly with similar teeth 35 formed on the movable jaw shank13 and whereby the movable jaw is held from outward movement when in use or when'set for use by the looking device 14-. By depressing the tailpiece 32 toward the shank 12, the yoke is swung in a clockwise direction around its pivot 19 causing the teeth 34 to disengage the teeth 35. In this position the movable jaw is free to slide freely outwardly as far as desired or until it is stopped by a pivot screw 36 projecting through the inner end of the shank 13 and adapted to abut against the edge 16 just described. In order to remove the movable jaw, the-screw is taken outsetting the shank 13free for endwisemovement and then the dog may be easily removed as before described and another put in its place. While, however, the shank 13 remains in its place between the plates16 of the yoke, it is impossible for the dog to be :1. come-displaced or loose for the reason that the point 30 "can by no possibility drop sufkfieiently far towardthe stationary jaw to pass theplate 17 and inasmuch as the hook 31 always embraces the round edge 17 of sald plate, force applied upon the tail piece cannot permit themovement ofthe dog in? dependently of the yoke itself. In other words, the hook and ro'unded'edge '17 constitute a fixed connection for the dog for all practical purposes whether the shoulders 33 be used or not, but I prefer to use the shouL ders because a-more satisfactory connection 1s made thereby with the yoke. I wish, to

'plate' edge.

3. In a quick-adjustment wrench of the.

emphasize particularly several advantages for this improved structure. First, the yoke being made in one piece lncludmg the plate 17 is exceedingly simple and easy to make and possesses the maximum strength. Again, the dog being made separate and separable from the yoke is preferably of a superior quality of steel with the teeth thereof hardened and if the same should become formed on one face of the body and extend ing from one side to the'other, there being provlded" a pair of outward pro ections on the face opposite the toothed face, one ofsaid'projections being undercut, laterally projecting shoulders formed at the ends of "said flat sides, and av tail piece extending from the end of the body having the undercut projection and between the shoulders, substantially as set forth. 7 V

2. The combination. with a stationary member, a member movable with respect thereto and a yoke pivoted to said stationary member and loosely embracing the movable 'member, said yoke comprising a fiat plate and side plat-es integral therewith, said plate having a SQIIll-CYlllldllCEl-l inner edge extending between the side plates, and a detachable looking dog fitted between saidside plates and having extensions engageable withthe innerand Outer edges of said plate, one of said extensions being undercut to engage over and interlock with said inner edges forming a pivot bearing around which the dog is tiltable, and a tail piece extending inwardly from the latter mentioned exten-' sion, the tail piece being so disposed that pressure thereon serves to mamtam the other extension 1n engagement with the outer character set forth, the combination with relativelystationary and movable members and a unitary loop-shaped yoke surrounding said members and pivoted to one of them,

said yoke having a pair of parallel side plates with inclined inner edges, of a de tachable locking dog fitted between said side plates and having interlocking engagement therewithfsaid dog having laterallyproj'ecting shoulders fitted. normally squarely against said inclined edges, said dog also being provided with an inwardly projecting rigid tail piece, pressure upon which isresisted by said shoulders. 7

- HENRY F. HOFFMAN.

Copies of this patent may be obtained for five cents each, by addressing; the Commissioner of Patents, Washington, D. 0. 

